John H. Chafee, 77, a moderate Republican senator from Rhode Island who often piqued his party with his independent stances and championed environmental issues, died of congestive heart failure Oct. 24 at Bethesda's National Naval Medical Center. He lived in McLean and Warwick, R.I.

Sen. Chafee, who was elected in 1976, served as chairman of the Senate Committee on Environment and Public Works. He joined the committee in 1977 and made environmental matters a chief concern, often breaking with his party to the delight of conservation groups.

"His fingerprints are over all the major environmental legislation passed in the last 20 years," said Darrell West, a professor of political science at Brown University and a Rhode Island political analyst, who interviewed Sen. Chafee last year.

Among the measures Sen. Chafee fostered while in the minority were the Clean Water Act of 1986, the Oil Pollution Act of 1990 and amendments to the Clean Air Act of 1990. He also was a sponsor of the legislation that created the Superfund program in 1980 to clean up hazardous waste sites and was involved in every revision since then.

In March, Sen. Chafee announced that he would step down at the end of his current term rather than run for reelection in 2000.

Sen. Chafee supported issues as varied as the North American Free Trade Agreement and the right to an abortion. In recent weeks, he was in favor of debating on the Senate floor the Nuclear Test Ban Treaty, but that effort was killed largely by more conservative Republicans in the Senate.

This fall, Sen. Chafee and Democratic Sen. Bob Graham of Florida unsuccessfully sponsored a compromise health-care reform bill that would have given customers an independent appeals process and the right to sue health insurance companies in federal court. In 1993 and 1994, he also lost favor among his Republican peers by advocating a universal health-care system.

His moderate stances increasingly alienated him from his party's leadership, West said. Still, he said a September survey sponsored by Brown found that Sen. Chafee had an approval rating of 63 percent among Rhode Island voters.

Sen. Chafee lost his position in 1990 as chairman of the Senate Republican Conference, the party's third-highest leadership post, by one vote to Sen. Thad Cochran of Mississippi.

On Monday, Cochran spoke admiringly of Sen. Chafee in an interview. "I thought he was a very important member of the Senate because of his active influence and his willingness to take stands that were not always popular," Cochran said.

Sen. Chafee told The Post in February that he did not feel that he represented the wrong party, despite his disagreements with its leaders about President Clinton's impeachment, abortion, tax cuts, gun control and environmental issues. "I'm happier being a Republican than a Democrat," he said. "That doesn't mean I'm happy with everything the Republicans do."

Sen. Chafee sat on the Select Committee on Intelligence and was chairman of the Senate Finance Committee's subcommittee on health care, but his biggest imprint was on environmental concerns.

"He was a pillar of strength defending environmental protections against the erosion being called for by the leaders in his own party – for example, protecting wetlands, defending the Clean Water Act," said Brent Blackwelder, president of Friends of the Earth, an environmental advocacy group.

Blackwelder was a squash partner of Sen. Chafee's until the senator stopped playing about seven years ago. "He was a vigorous man," Blackwelder said.

John Lester Hubbard Chafee was born Oct. 22, 1922, in Providence to a wealthy and politically active family. His great-grandfather Henry Lippitt was a Rhode Island governor, and among his great-uncles were a Rhode Island governor, Charles Lippitt, and a United States senator, Henry F. Lippitt.

Sen. Chafee served in the Marines during World War II and was a Marine rifle company commander in the Korean War.

In 1940, he graduated from Deerfield Academy, a private school in Massachusetts. He received degrees from Yale University in 1947 and Harvard University law school in 1950.

Sen. Chafee became active in behind-the-scenes Rhode Island politics by helping elect a mayor of Providence in the early 1950s.

He successfully ran for a seat in the Rhode Island House of Representatives in 1956 and later became the minority leader. He was reelected in 1958 and 1960, the latter a year when many Republicans were swept from office in his state.

Sen. Chafee was elected governor in 1962, and he helped create the state's public transportation administration as well as what was known as the Green Acres program, a conservation effort. Sen. Chafee was named chairman of the National Association of Republican Governors in 1967.

He was defeated in his bid for reelection as governor in 1968 after advocating a state income tax, which did pass a few years later. His appointment as secretary of the Navy in 1969 was a "consolation prize to keep him in public service," said West, the Brown professor.

Sen. Chafee wasn't an obvious choice for the Navy Department job because he had backed Nelson Rockefeller against Richard Nixon for the 1968 Republican presidential nomination, Navy Times wrote in 1972. He also was critical of Spiro Agnew as Nixon's vice presidential nominee.

Four months into his job, Sen. Chafee had to face the case of the USS Pueblo, a Navy intelligence ship seized by the North Koreans in what were thought to be North Korean waters.

The Pueblo crew was held for many months and then released, and the Navy established a court of inquiry. The court recommended two courts-martial, two letters of reprimand and a letter of admonition for five officers. That was reduced to letters of reprimand for three officers, a letter of admonition for one and no penalty for another.

Sen. Chafee decided to end proceedings, saying the months of captivity were punishment enough. "The consequences must in fairness be borne by all, rather than by one or two individuals whom circumstances had placed closer to the crucial event," he told Navy Times.

Sen. Chafee left the Navy Department in 1972 to run, unsuccessfully, against Democratic Sen. Claiborne Pell. In 1976, he filled the seat vacated by Democratic Sen. John Pastore.

His last major act was authoring and sponsoring the Transportation Equity Act for the 21st Century, which authorizes funding for transportation programs for the next six years. As part of that act, Sen. Chafee pushed for a 60 percent increase in funding – to $1.5 billion – for projects to alleviate air-quality and congestion problems in transportation.

The equity act, including Sen. Chafee's provision, was signed by Clinton in June.

Survivors include his wife, Virginia Coates Chafee of McLean and Warwick; a daughter, Georgia Nassikas of McLean; four sons, John Jr., of Los Angeles, Lincoln, of Warwick, Quentin, of North Kingstown, R.I., and Zechariah, of Providence; three sisters; and 12 grandchildren.